Good day, I am trying to educate myself, so please forgive me if the following falls short in some way.
Can someone please tell me if there was a difference in the trigger guard bluing used on LC Smith Field grades manufactured 1945-1946 and the trigger guard bluing used 1940-1941? Hunter vs Marlon eras. I am looking at two field grades from the abovementioned timeframes. I think both are original. I notice that the 40-41 trigger guard bluing is definitely bluer than the 45-46 guard. The 45-46 guard looks blacker. Is this a normal observation, in general?
I do sincerely appreciate any input you all can offer me.

Barry Thomas
skeetbt1@gmail.com